Long Term Evolution (LTE) is long term evolution of Universal Mobile Telecommunications System (UMTS) technical standards, and is developed by the 3rd Generation Partnership Project (3GPP) organization. In an LTE network, when a user equipment (UE) moves from a coverage area of a base station managed by a mobility management entity (MME) to a coverage area of another base station during movement, hard handover processing needs to be performed.
A main working principle of hard handover performed for a UE is as follows: the UE first measures signal strength of a current serving cell, measures signal strength of a neighboring cell of the current serving cell when the signal strength of the current serving cell is lower than a first specified threshold, and reports a measurement result of the UE to a source base station. The source base station determines, based on the signal strength of the neighboring cell obtained through measurement, a target base station to which the UE may be handed over; and when the signal strength of the current serving cell is lower than a second specified threshold, generates a handover request and sends the handover request to the target base station. The target base station performs admission control according to the handover request, and sends a handover acknowledgment message to the source base station. Then, the source base station sends a handover command to the UE. After receiving the handover command, the UE immediately disconnects a connection to the source base station, and is uplink synchronized with the target base station in a random access mode. After successful random access, the UE can communicate with the target base station.
However, in the hard handover mode, after disconnecting the connection to the source base station, the UE accesses the target base station by using a random access procedure. Therefore, a relatively great latency is caused.